I am having difficult in getting my truck to fire!!! i have pressure in the fuel rail to the injectors!! Injector wiring harness is all plugged in!! there is spark!! firing order is correct!!
It seems to me that the injectors are not injecting!! What could be wrong???

Thanks for all you info!!

Jared, PSU Tailgater!!

88 F150 5.0 HO

 

 

I'll take a stab in the dark that you're chasing the wrong problem. If you have pressure to the rails, and the harness is plugged in correctly, it's probably not the problem. If you still think it may be, pull all of your injectors and take them to a shop that will do a flow test on them.
Okay, on to trouble shooting. Where is there spark? At the coil? The cap? The plug wires? The plugs? Are all of the plugs in good condition? Have you tried cranking it at night to watch for a light show while cranking?
Have you checked that the air intake isn't clogged?
Next, have you recently had the engine apart? Have you recently had the distributor out? If yes, was the distributor reinstalled correctly? Could the timing be off? Could there be damage to a valve or two due to a mis-timed engine?
Big question, is this a new developement, or was it previously having dificulty starting? If it's just started suddenly, what did you do to it to make it suddenly stop working?

 

Just to make sure, 302 HO has 351W firing order, Also it could be an electrical problem. To see if the electricty is getting to an injector unplug the wire at one injector, have someone else crank the engine. While this is happening use a test light, ground the clip end to a good ground and probe the injector clip, one side is ground the other power. If you don't get a flashing light on either wire then you are not getting the single. If this is the case you need to back probe the harness till you geet power. Another place I would look at is the main connection from the computer to the injectors and sensors. I know on mine (86) that there are two connections side by side one black the other is white. I would disconnect them and look inside for corrosion. Then reconnect making sure of a tight connection. Hope this helps, if not let me know and I may be of more help.
Robert